Comparative Carbon Footprint Assessment of Winter Lettuce Production

Comparative Carbon Footprint Assessment of Winter Lettuce Production in two Climatic Zones for Midwestern Market

AbstractThe following study assesses cold-season hoop house lettuce production in the context of local food systems’ relative environmental effects. For this purpose, we compare the carbon footprints of leaf lettuce production in two climatic zones, one close to the consumer market and one distant, via environmental impact modeling in SimaPro 7.3. A site-specific scenario is first detailed with organic leaf lettuce locally grown in an East Lansing, Michigan hoop house. This is compared to a hypothetical scenario, modeled using average industry data, with leaf lettuce conventionally grown in California then shipped to East Lansing. The system boundaries used in this analysis extend from manufacturing of farm production inputs to a hypothetical retail gate. We assumed that the consumer drove the same distance to the retailer in each case. The functional unit used is 1 kg of leaf lettuce. Results demonstrate that the distant system exhibits 4.3 times the CO2 ‘footprint’ per kg of lettuce. This nonlocal system also resulted in higher resource depletion, health impact and ecological damage potential as demonstrated via the SimaPro simulation. This study concludes that unheated, hoop house lettuce production, given the assumption on within-area travel, has a smaller carbon footprint than outdoor, distant production, and speaks to both the potential value of more localized food systems and the need for a more diverse set of scenario modeling to understand the boundaries of this value.